Upon driving my car(01 430) the other day, I decided to gun it after a light. I mean come on, what else are you supposed to do when driving a merc? Anyway, as i let off the gas I experienced a backfire followed momentarily with flames... I'd just like to know if this has happened to anyone else and if so, what the problem was. Do you think it could be the cat or just timing?

 

how did you see the flames? sounds like you are running way too rich.

 

Yeah i should probably clear that up, my following friend saw the flame, not me.

So basically theres too much fuel,(i.e running rich) but shouldn't the cat burn that off?

 

Gasoline requires oxygen to burn. It sounds like you're running rich and the fuel wouldn't ignite until heated gasoline vapors were in the air, which is about 20% oxygen.

 

once i ran mid grade gas in an supercharged olds and it backfired on me a few time. are you running 91+?

 

yeah I always try to run 91+ even though gas is pretty expensive. Don't want any long term effects of being cheap at the pump